The Role of Genetics in Predictive and Personalized Medicine of Rheumatoid Arthritis

Recent progress of genetics has dramatically improved pharmacogenetics for human diseases. Several pharmacogenetic assays such as TPMT/azathioprine and CYP2C9/VKORC1/warfarin have been introduced in clinical practice at the present time. Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that leads to irreversible joint damage and disability if it is not adequately treated. Although the introduction of anti-TNF therapy has improved the outcome of therapy in RA, a substantial proportion of patients (approximately 30-40%) fail to respond to the drugs. Recently, pharmacogenetic studies have widely been performed to search for genetic and mRNA expression biomarkers to predict the response of anti-TNF therapy in RA. Other potential serum biomarkers of response have also been explored including cytokines and autoantiboides. None has yet been validated for biomarkers that predict the response of biologic drugs in clinical rheumatology practice. However, future medicine using pharmacogenetic applications in RA might make personalized therapy possible.